[Recovery after gynaecological surgery in French-speaking Belgium : survey and recommendation of the GGOLFB surgical working group]

Since the introduction of laparoscopy and mini-invasive techniques, gynaecological surgery has largely evolved. However, post-operative recommendations still remain very restrictive with poor evidence from literature. The survey, performed by the GGOLFB surgical working group, shows that the post-operative advices to the patients are very heterogeneous for the sick leave period as for more specific advices like the period of disallowance of sexual intercourse, bathing and weightlifting. It is nevertheless fundamental to prescribe clear and precise advices to patients, from the first pre-operative consultation on, which will substantially improve the perception of their recovery and promote a return to their normal activity under good conditions. It is not necessary to be too restrictive concerning certain activities in the post-operative period, neither to give too long periods of work incapacity because it may have a negative impact on their quality of life. This survey and the data from literature helped our surgical taskforce group to propose and develop harmonised recommendations on recovery and work incapacity after gynaecological surgery, taking into account the actual surgical practice in 2020.

[Prolapse and urinary incontinence in women : place of the general practitioner]

The ageing of the population, having access to good quality of care, will result in an increase in the prevalence of pelvic floor diseases. Those persons, often in good general health, may experience difficulties in accepting functional pathologies, associated with loss in quality of life. One out of 2 women will have a pelvic floor problem and 1 out of 9 will have a surgical perineal procedure before the age of 80 years. The unitary character of the pelvic floor, a complex functional anatomic region, is often forgotten, essentially because the patients complain about one main pathology like urinary incontinence, genital prolapse, constipation and sexual disorders or chronic pain and will consult one specific specialist. Our role as health care professionals is to be aware of those associated pathologies and to obtain an optimal quality of care. The actual evolution towards specific clinical pathways with the integration of office provided care outside the hospital, needs to become the new standard of care. We try to give an overview of the different preventive, diagnostic and therapeutic options, available in a general practitioner's office. Taking care of the pelvic floor needs to be done in a global and pluridisciplinar setting. Referring towards specialised centres as well as the integration of the general practitioner, especially for the more complex cases, is essential.

Stromal SLIT2 impacts on pancreatic cancer-associated neural remodeling

Pancreatic ductal adenocarcinoma (PDA) is a critical health issue in the field of cancer, with few therapeutic options. Evidence supports an implication of the intratumoral microenvironment (stroma) on PDA progression. However, its contribution to the role of neuroplastic changes within the pathophysiology and clinical course of PDA, through tumor recurrence and neuropathic pain, remains unknown, neglecting a putative, therapeutic window. Here, we report that the intratumoral microenvironment is a mediator of PDA-associated neural remodeling (PANR), and we highlight factors such as 'SLIT2' (an axon guidance molecule), which is expressed by cancer-associated fibroblasts (CAFs), that impact on neuroplastic changes in human PDA. We showed that 'CAF-secreted SLIT2' increases neurite outgrowth from dorsal root ganglia neurons as well as from Schwann cell migration/proliferation by modulating N-cadherin/β-catenin signaling. Importantly, SLIT2/ROBO signaling inhibition disrupts this stromal/neural connection. Finally, we revealed that SLIT2 expression and CAFs are correlated with neural remodeling within human and mouse PDA. All together, our data demonstrate the implication of CAFs, through the secretion of axon guidance molecule, in PANR. Furthermore, it provides rationale to investigate the disruption of the stromal/neural compartment connection with SLIT2/ROBO inhibitors for the treatment of pancreatic cancer recurrence and pain.

Consequences of DJ-1 upregulation following p53 loss and cell transformation

p53 is a tumor suppressor that responds to various stress signals by initiating cell-cycle arrest, senescence and apoptosis. Mutations of the p53 gene are found in over 50% of human tumors, highlighting the importance of p53 in tumor suppression. Numerous studies have reported on the interactions between p53, IGF-1-AKT and mTOR pathways as potentially explaining some of the tumor suppressive activities of p53. To further understand the basis of these interactions, we analyzed the involvement of DJ-1, an oncogene known to drive AKT-mediated cell survival, in the p53-AKT axis. In this study, we show that DJ-1 and p53 are tightly 'linked': p53 prevents the accumulation of DJ-1 protein, whereas loss of p53 leads to stabilization and enhancement of DJ-1 expression. Interestingly, this increase in DJ-1 level is only observed when p53 loss is accompanied by transformation of cells. Moreover, DJ-1 seems to be required for the enhanced activation of AKT observed in p53-deficient cells. Such observation confers a new property to DJ-1 associated to transforming-process to its oncogenic ability to drive AKT activation. We also show that DJ-1 is necessary for p53 activation following oxidative stress, suggesting the existence of a finely regulated loop between these two proteins in transformed cells. Finally, we demonstrate that in the absence of p53, DJ-1 is stabilized by ROS accumulation, and surprisingly seems to be required for this high intracellular ROS production. These data offer new insights into the regulation of DJ-1 and suggest that DJ-1 is a target of p53. Importantly, our study highlights that during transformation, DJ-1 is having a key role in the p53-regulated AKT pathway and p53-driven oxidative-stress response.

Silica encapsulated manganese perovskite nanoparticles for magnetically induced hyperthermia without the risk of overheating

Nanoparticles of manganese perovskite of the composition La(0.75)Sr(0.25)MnO(3) uniformly coated with silica were prepared by encapsulation of the magnetic cores (mean crystallite size 24 nm) using tetraethoxysilane followed by fractionation. The resulting hybrid particles form a stable suspension in an aqueous environment at physiological pH and possess a narrow hydrodynamic size distribution. Both calorimetric heating experiments and direct measurements of hysteresis loops in the alternating field revealed high specific power losses, further enhanced by the encapsulation procedure in the case of the coated particles. The corresponding results are discussed on the basis of complex characterization of the particles and especially detailed magnetic measurements. Moreover, the Curie temperature (335 K) of the selected magnetic cores resolves the risk of local overheating during hyperthermia treatment.

Molecular basis of the Li-Fraumeni syndrome: an update from the French LFS families

We have performed an extensive analysis of TP53 in 474 French families suggestive of Li-Fraumeni syndrome (LFS), including 232 families fulfilling the Chompret criteria. We identified a germline alteration of TP53 in 82 families (17%), in 67/232 of the families fulfilling the Chompret criteria (29%) and in 15/242 which did not fulfil these criteria (6%). Most of the alterations corresponded to missense mutations (67%), and we identified in four families genomic deletions removing the entire TP53 locus, the promoter and the non-coding exon 1, or exons 2-10. These results represent a definitive argument demonstrating that LFS results from TP53 haplodeficiency. The mean ages of tumour onset were significantly different between patients harbouring TP53 missense mutations and other types of alterations, missense mutations being associated with a 9 year earlier tumour onset. These results confirm that missense mutations not only inactivate p53 but also have an additional oncogenic effect. Germline alterations of TP53 that lead exclusively to loss of function are therefore associated with a later age of tumour onset and the presence of such mutations should be considered in atypical LFS families with tumours diagnosed after 40 years.

Sr-hexaferrite/maghemite composite nanoparticles-possible new mediators for magnetic hyperthermia

Composite nanoparticles with variable ratios of M-type Sr-hexaferrite and maghemite phases were prepared via the sol-gel method employing polyvinylalcohol as the stabilizing agent, followed by thermal treatment at 600 °C for 32-190 min. The measurements in static magnetic field revealed considerable variation of the coercivity and remanence depending on the relative content of the highly magnetically anisotropic Sr-hexaferrite phase. Calorimetric heating experiments were carried out on aqueous gel suspensions under an alternating magnetic field of maximum amplitude H(max) = 15.1-68.4 kA m(-1) and frequency ν = 108 kHz. They showed a strong dependence of the heating efficiency on the coercivity and remanence of the composites, with a specific absorption rate (SAR) value ranging from units to tens of W/g(Fe(ferrimagnetic)).

Effects of dietary fibre and feeding frequency on wool biting and aggressive behaviours in housed Merino sheep

Wool biting is a behaviour that can develop in housed sheep, in which sheep start to bite and eat the wool of others. The aim of this study was to determine whether (i) supplementing the diet of housed sheep with fibre and (ii) increasing feeding frequency would help to reduce wool biting, aggressive behaviours and wool damage. In a 2 × 2 factorial experiment, 40 Merino wethers were either fed with lucerne-based pellets only, or with pellets supplemented with barley straw. They received their pellets either on a low feeding frequency basis (once a day Monday to Friday mornings, double ration on Friday afternoon, nothing Saturdays and Sundays), or on a high feeding frequency basis (twice a day, every day). The sheep were housed in 4 treatment pens, each with 10 animals. Wool biting and aggressive behaviours were recorded through direct observation and the sheep were scored for wool damage twice a week during the 15-week study. The provision of fibre had a significant effect on reducing wool biting (P<0.001) and wool damage score (P<0.001). There was no consistent effect of feeding frequency on wool biting or wool damage, and no fibre × feeding frequency interactions. Whereas wool biting in general increased with time during the study (P<0.001), levels of aggressive behaviour showed no consistent time trend, and there were no effects of fibre or feeding frequency treatments. It is concluded that wool biting is largely a redirected behaviour in concentrate-fed housed sheep deprived of adequate levels of activity or oral stimulus, and that the provision of roughage will reduce the development of wool biting and improve animal welfare in housed experimental sheep.

Impact of the MDM2 SNP309 and p53 Arg72Pro polymorphism on age of tumour onset in Li-Fraumeni syndrome

Li-Fraumeni syndrome, resulting from p53 (TP53) germline mutations, represents one of the most devastating genetic predispositions to cancer. Recently, the MDM2 SNP309 (T-->G variation) was shown to be associated with accelerated tumour formation in p53 mutation carriers. The impact of the common p53 codon 72 polymorphism on cancer risk remains controversial. We therefore investigated the effect of these two polymorphisms in 61 French carriers of the p53 germline mutation. The mean age of tumour onset in MDMD2 SNP309 G allele carriers (19.6 years) was significantly different from that observed in patients homozygous for the T allele (29.9 years, p<0.05). For the p53 codon 72 polymorphism, the mean age of tumour onset in Arg allele carriers (21.8 years) was also different from that of Pro/Pro patients (34.4 years, p<0.05). We observed a cumulative effect of both polymorphisms because the mean ages of tumour onset in carriers of the MDM2G and p53Arg alleles (16.9 years) and those with the MDM2T/T and p53Pro/Pro genotypes (43 years) were clearly different (p<0.02). Therefore, our results confirm the impact of the MDM2 SNP309 G allele on the age of tumour onset in germline p53 mutation carriers, and suggest that this effect may be amplified by the p53 72Arg allele. Polymorphisms affecting p53 degradation therefore represent one of the rare examples of modifier genetic factors identified to date in mendelian predispositions to cancer.

Choosing where to deliver: decision criteria among women with low-risk pregnancies in France

As in the rest of Europe, the supply of maternity hospitals has progressively decreased over the past few decades in France. An understanding of user choice criteria is important to help health planners reorganize obstetrical services and to predict changes in utilization patterns in response to supply changes. The objectives were to understand the criteria that women use to select their maternity hospital in France and to analyse the relation to individual and community characteristics. A survey of 536 recently delivered women with low-risk pregnancies explored the factors motivating user choice in three territories with distinct geographical and health service supply characteristics: four districts in Burgundy, two districts in Pays de la Loire, and the district of Seine-Saint-Denis in Ile-de-France. Women were asked to select a principal choice criterion. Their responses were grouped into categories: Accessibility/proximity, reputation of the establishment among users, advice of treating physician, technical quality and cost. Accessibility and proximity were the most selected criteria (33%), followed by the reputation of the maternity (29%), technical quality (15%) and advice of treating physician (13%). Age, parity and education influenced choice criteria. After controlling for individual determinants, region of residence was highly related to choice criteria; women living in Burgundy were more likely to select an establishment based on proximity, in Seine-Saint-Denis women were more likely to follow the advice of their physician, and in Pays de la Loire, more likely to base their decisions on the reputation of the establishment. The association between choice criteria and community characteristics could explain the failure of previous models to predict behaviour in different contexts. It is important to carry out local surveys of user perceptions before restructuring in order to take into consideration women's opinions on their future places of delivery and to refine geographic models.

Expression of the stress-induced p8 mRNA is transiently activated after culture medium change

We report here that the mere fact of changing culture medium for fresh medium induced in several cell lines the expression of stress-activated genes including protein kinases p38, JNK and ERK1/2 and the transcription factor C/EBPbeta. As a consequence, p8, a gene induced by stress in several tissues, was strongly up-regulated. Induction did not occur after change for cell-conditioned medium. Induction was however transient, with a peak at 60 min for p38, at 15-30 min for JNK and at 15 min for ERK1/2, at 2-3 hours for C/EBPbeta and at 4-6 hours for p8. Repression of the induction was due to the secretion of thermolabile molecule(s) that progressively conditioned the medium. As low as 25% of conditioned medium added to fresh culture medium was sufficient to abolish the stress response. Taken together, our data indicate that the renewal of culture medium induces a transient cellular stress that may be a source of artifacts in experiments performed shortly after a change of culture medium.

Transforming growth factor beta-1 enhances Smad transcriptional activity through activation of p8 gene expression

We report that exposure of mouse embryonic fibroblasts to transforming growth factor beta-1 (TGFbeta-1) (5 ng/ml) results in a strong activation of p8 mRNA expression that precedes the induction of cell growth. Involvement of the p8 promoter in the regulation was demonstrated by using a p8-chloramphenicol acetyltransferase construct. We therefore speculated that p8 might be a mediator of TGFbeta-1 in these cells. The incorporation of [(3)H]thymidine on treatment with TGFbeta-1 was indeed significantly higher in p8(+/+) fibroblasts than in p8(-/-) fibroblasts. Smad transcriptional activity was used as marker of the TGFbeta-1 signalling pathway, to probe the lower p8(-/-) response to TGFbeta-1. Two Smad-binding elements (SBEs)-luciferase constructs were transfected into p8(-/-) and p8(+/+) embryonic fibroblasts before treatment with TGFbeta-1. A lower level of Smad transactivation was observed in p8(-/-) embryonic fibroblasts, under basal conditions and after stimulation with TGFbeta-1. To test whether Smad underexpression in p8(-/-) cells was actually due to p8 depletion, p8(-/-) embryonic fibroblasts were transfected with a human p8 expression plasmid together with an SBE-luciferase construct. The expression of p8 restored Smad transactivation in unstimulated and TGFbeta-1-treated cells to the level found in p8(+/+) cells. We concluded that TGFbeta-1 activates p8 expression, which in turn enhances the Smad-transactivating function responsible for TGFbeta-1 activity.

Pancreatitis associated protein I (PAP-I) alters adhesion and motility of human melanocytes and melanoma cells

Pancreatitis associated protein I is a secretory stress protein first characterized in pancreas during pancreatitis but also expressed in several tissues including hepatic, gastric, and colon cancer. Its concentration in serum can be significant. The relationship of pancreatitis associated protein I to skin cancers was investigated in normal melanocytes, melanoma tumors, and melanoma cell lines. None of them expressed pancreatitis associated protein I, even after stress induction. Adenovirus-mediated pancreatitis associated protein I expression, however, reduced cell adhesion to laminin-1 and fibronectin with a loss of integrin participation. Pancreatitis associated protein I expression stimulated haptotactic and directed migrations of some melanoma cells, but only directed migration was activated in normal melanocytes. Importantly, directed migration and spreading on fibronectin of the responsive melanoma cells were also enhanced when purified rat pancreatitis associated protein I was added to the culture medium of noninfected cells. This indicates that effects in infected cells were elicited by pancreatitis associated protein I after its secretion. Exogenous pancreatitis associated protein I can therefore modify the adhesion and motility of normal and transformed melanocytes, suggesting a potential interaction with melanoma invasivity.

Cdx1 promotes cellular growth of epithelial intestinal cells through induction of the secretory protein PAP I

Expression of the Cdx1 homeobox gene in epithelial intestinal cells promotes cellular growth and differentiation. Cdx1and the Pancreatitis Associated Protein I (PAP I) are concomitantly expressed in the epithelial cells of the lower part of the intestinal crypts. Because Cdx1 is a transcription factor and PAP I, in other tissues, is a proliferative factor, we looked for a relationship between these two proteins in the intestinal-derived IEC-6 cells. After stable transfection with a Cdx1 expression vector, they produce high levels of the PAP I transcript and protein indicating a functional link between the two genes. Demonstration of Cdx1 binding to the PAP I promoter region and suppression of PAP I induction after deletion of the corresponding sequence indicated that Cdx1 is a transcription factor controlling PAP I gene expression in intestinal cells. By infecting IEC-6 cells with adenoviruses expressing PAP I, we demonstrated that PAP I induces mitosis in these cells. On the other hand, inhibition of the PAP I expression in the IEC-6 Cdxl-expressing cells using an antisense strategy confirmed the requirement of this protein for the effect of Cdx1 on cell growth. Finally, addition of the immunopurified PAP I to the culture medium promotes cell growth of the IEC-6 cells in a dose-dependent manner. Maximal effect was obtained at 1 ng/ml. Taken together these results demonstrate that PAP I is a target of the Cdx1 homeobox gene in intestinal cells which participates in the regulation of intestinal cell growth via an autocrine and/or paracrine mechanism.

Reg-2 is a motoneuron neurotrophic factor and a signalling intermediate in the CNTF survival pathway

Cytokines that are related to ciliary neurotrophic factor (CNTF) are physiologically important survival factors for motoneurons, but the mechanisms by which they prevent neuronal cell death remain unknown. Reg-2/PAP I (pancreatitis-associated protein I), referred to here as Reg-2, is a secreted protein whose expression in motoneurons during development is dependent on cytokines. Here we show that CNTF-related cytokines induce Reg-2 expression in cultured motoneurons. Purified Reg-2 can itself act as an autocrine/paracrine neurotrophic factor for a subpopulation of motoneurons, by stimulating a survival pathway involving phosphatidylinositol-3-kinase, Akt kinase and NF-kappaB. Blocking Reg-2 expression in motoneurons using Reg-2 antisense adenovirus specifically abrogates the survival effect of CNTF on cultured motoneurons, indicating that Reg-2 expression is a necessary step in the CNTF survival pathway. Reg-2 shows a unique pattern of expression in late embryonic spinal cord: it is progressively upregulated in individual motoneurons on a cell-by-cell basis, indicating that only a fraction of motoneurons in a given motor pool may be exposed to cytokines. Thus, Reg-2 is a neurotrophic factor for motoneurons, and is itself an obligatory intermediate in the survival signalling pathway of CNTF-related cytokines.

Tumor necrosis factor alpha triggers antiapoptotic mechanisms in rat pancreatic cells through pancreatitis-associated protein I activation

BACKGROUND & AIMS

Tumor necrosis factor (TNF)-alpha contributes to the development of acute pancreatitis. Because TNF-alpha is involved in the control of apoptosis, we studied its interaction with the pancreatic apoptotic pathway.

METHODS

Pancreatic acinar AR4-2J cells were used. Apoptosis was monitored by morphologic and biochemical criteria.

RESULTS

TNF-alpha induced apoptosis in AR4-2J cells. Induction was strongly enhanced in cells treated with actinomycin D, suggesting that TNF-alpha activated concomitantly an antiapoptotic mechanism through newly synthesized proteins. This mechanism involved activation of nuclear factor-kappaB (NF-kappaB) and mitogen-activated protein (MAP) kinases because their inhibition worsened TNF-alpha-induced apoptosis. The antiapoptotic pancreatitis-associated protein (PAP) I is a candidate for mediating TNF-alpha activity. Its expression is induced by TNF-alpha, and cells overexpressing PAP I show significantly less apoptosis on exposure to TNF-alpha. We examined whether TNF-alpha induction of PAP I expression was mediated by NF-kappaB or MAP kinases by using specific inhibitors of both pathways. Inhibition of NF-kappaB had no effect. However, inhibitors of MEK1 eliminated PAP I induction.

CONCLUSIONS

TNF-alpha induces concomitantly proapoptotic and antiapoptotic mechanisms in pancreatic AR4-2J cells. Antiapoptotic mechanisms are mediated by NF-kappaB and MAP kinases, and PAP I is one of the effectors of apoptosis inhibition.

Structural and functional characterization of the mouse p8 gene: promotion of transcription by the CAAT-enhancer binding protein alpha (C/EBPalpha) and C/EBPbeta trans-acting factors involves a C/EBP cis-acting element and other regions of the promoter

Rat p8 mRNA was discovered because of its strong activation in pancreas during the acute phase of pancreatitis. We report here structural and functional data on the mouse p8 gene. The mouse p8 polypeptide is 80 amino acids long and shows 91% and 75% identity with its rat and human counterparts respectively. The p8 gene is organized into three exons interrupted by two introns. Promoter regions involved in the regulation of p8 gene expression in NIH 3T3 cells were analysed. Chloramphenicol acetyltransferase (CAT) reporter assays with progressive deletions of the 5' flanking region of the mouse p8 gene revealed four silencer elements located from nucleotides -5000 to -1472, -1471 to -671, -670 to -473, and -239 to -117 respectively. One positive element was identified between nucleotides -117 and -72. We identified a CAAT-enhancer binding protein (C/EBP) cis-acting element at position -111. Site-directed mutagenesis of this consensus site decreased promoter activity to 5% of that of the wild-type. An electrophoretic mobility-shift assay, using an oligonucleotide probe corresponding to the C/EBP consensus and nuclear extracts of NIH 3T3 cells transfected with C/EBPalpha or C/EBPbeta expression vectors, generated specific DNA-protein complexes that were supershifted with specific antibodies against C/EBPalpha and C/EBPbeta. Co-transfection with C/EBPalpha or C/EBPbeta expression vectors and the p-116/+36p8-CAT construct increased the reporter gene activity in a dose-dependent fashion. Surprisingly, overexpression of C/EBPalpha or C/EBPbeta still increased the promoter activity of both pC/EBPmut-116/+36p8-CAT (which contains the C/EBP mutated site) and the p-71/+36-CAT construct (which does not contain the C/EBP site). Collectively, these results show that C/EBPalpha and C/EBPbeta trans-acting factors can promote transcription of the mouse p8 gene (i) by direct binding to the C/EBP consensus site, and (ii) by enhancing the activity of other trans-acting factors interacting with the p8 promoter.

pap, reg Ialpha and reg Ibeta mRNAs are concomitantly up-regulated during human colorectal carcinogenesis

We have established the phenotype of a colorectal tumor by partial sequencing of 2166 transcripts that were eventually arrayed on high-density filters. These filters were used for differential screening with mRNAs of colorectal cancer and normal adjacent mucosa to characterize genes whose expression is altered in colorectal carcinoma. Three genes encoding related proteins, PAP, reg Ialpha and reg Ibeta, were over-expressed in cancer. Northern-blot analysis confirmed that their expression was very low in normal colonic epithelial cells, but elevated in 75% of tumors. Western blotting with specific antibodies to pap and reg Ialpha revealed in tumors a single band of the expected size ( 15-16 kDa), demonstrating synthesis of the proteins. Pap was localized by immunohistochemistry to the cytoplasm of epithelial cells. In cancerous tissue, many cells showed a strong staining signal, but the proportion of stained cells was variable among patients. In normal mucosa, staining was light and restricted to a few cells scattered in the epithelium. Similar results were obtained with antibodies against reg Ialpha. No significant relationship was found between concentrations of pap, reg Ialpha or reg Ibeta and clinical outcome. We looked at potential effectors of pap/reg gene over-expression by testing, in 2 adenocarcinoma cell lines, the efficacy of the pap promoter at driving a reporter gene; strong induction was observed upon exposure to IFNgamma and IL-6. By analogy with observations in hepatocellular carcinoma, our results suggest that prevention of PAP/reg expression in normal colon cells by silencing their gene promoters is relieved during colon carcinogenesis, allowing their up-regulation by mediators such as cytokines.

pap, reg Ialpha and reg Ibeta mRNAs are concomitantly up-regulated during human colorectal carcinogenesis

We have established the phenotype of a colorectal tumor by partial sequencing of 2166 transcripts that were eventually arrayed on high-density filters. These filters were used for differential screening with mRNAs of colorectal cancer and normal adjacent mucosa to characterize genes whose expression is altered in colorectal carcinoma. Three genes encoding related proteins, PAP, reg Ialpha and reg Ibeta, were over-expressed in cancer. Northern-blot analysis confirmed that their expression was very low in normal colonic epithelial cells, but elevated in 75% of tumors. Western blotting with specific antibodies to pap and reg Ialpha revealed in tumors a single band of the expected size ( 15-16 kDa), demonstrating synthesis of the proteins. Pap was localized by immunohistochemistry to the cytoplasm of epithelial cells. In cancerous tissue, many cells showed a strong staining signal, but the proportion of stained cells was variable among patients. In normal mucosa, staining was light and restricted to a few cells scattered in the epithelium. Similar results were obtained with antibodies against reg Ialpha. No significant relationship was found between concentrations of pap, reg Ialpha or reg Ibeta and clinical outcome. We looked at potential effectors of pap/reg gene over-expression by testing, in 2 adenocarcinoma cell lines, the efficacy of the pap promoter at driving a reporter gene; strong induction was observed upon exposure to IFNgamma and IL-6. By analogy with observations in hepatocellular carcinoma, our results suggest that prevention of PAP/reg expression in normal colon cells by silencing their gene promoters is relieved during colon carcinogenesis, allowing their up-regulation by mediators such as cytokines.

Cloning and expression of the human p8, a nuclear protein with mitogenic activity

We have previously identified a new rat mRNA, provisionally named p8, which showed a strong, but transient, induction in the pancreas in response to acute pancreatitis. We report here the cloning and sequencing of the human p8 cDNA. The human p8 polypeptide is 82 amino acids long and shows an overall identity of 74% with the rat counterpart. The complete structure of the p8 gene was also established. The p8 gene comprises three exons separated by two introns and the gene was mapped to chromosome 16. Analysis of the p8 primary structure suggested the presence of a bipartite motif of nuclear targeting, indicating that p8 may function within the nucleus. This presumption has been confirmed by transfection of COS-7 cells with the p8 cDNA followed by immunostaining with specific antibodies. p8 mRNA expression is induced in some, but not all, cells by serum starvation and ceramide. To analyze the p8 function, we stably transfected HeLa cells with a p8 expression plasmid, and measured their growth and their sensitivity to apoptosis. Response to TNF alpha and staurosporine-induced apoptosis was not modified by p8 expression. However, cells expressing p8 grew significantly more rapidly.

PAP gene transcription induced by cycloheximide in AR4-2J cells involves ADP-ribosylation

We report in this paper that cycloheximide induces PAP mRNA expression in the pancreatic acinar cell line AR4-2J in a dose- and time-dependent manner. We analyzed whether stabilization of the PAP mRNA or the direct induction of its transcription contributed to the induction of PAP mRNA expression by the drug. We first infected the cells, which do not express PAP mRNA constitutively, with a recombinant adenovirus in which the PAP cDNA was subcloned downstream of the CMV promotor, to obtain high levels of transcript. Then, transcription was pharmacologically blocked, the cells were treated with cycloheximide, and the PAP mRNA concentration was monitored over 8 h by Northern blot. PAP mRNA concentration remained unchanged for 4 h and then decreased in both cycloheximide-treated and control cells, ruling out a significant contribution of posttranscriptional regulation in cycloheximide induction. Direct regulation of gene transcription is therefore likely and we investigated whether it could involve ADP-ribosylation. Cycloheximide-induced cells were treated with two chemical inhibitors of poly(ADP-ribose) polymerase. 3-Aminobenzamide inhibited 75% of PAP gene induction and 4-hydroxyquinazolone, the highly specific inhibitor of the enzyme, blocked almost completely PAP expression, suggesting that ADP-ribosylation was indeed required for the upregulation of PAP gene expression by cycloheximide.

The pancreatitis-associated protein is induced by free radicals in AR4-2J cells and confers cell resistance to apoptosis

BACKGROUND & AIMS

Free radicals are involved in the pathogenesis of acute pancreatitis, during which pancreatitis-associated protein (PAP)-I is overexpressed. We explored whether PAP-I expression could be induced by oxidative stress and whether it could affect apoptosis.

METHODS

AR4-2J cells were exposed to H2O2 or menadione, and PAP-I messenger RNA (mRNA) expression was analyzed by Northern blotting.

RESULTS

Maximal expression was observed with 0.1 mmol/L H2O2 or with 0.05 mmol/L menadione. Induction was detectable after 12 hours, reached a climax at 18 hours, and then decreased. Pretreatment of the cells with pyrrolidine dithiocarbamate completely abolished PAP-I mRNA induction, suggesting involvement of NFkappaB in the signaling pathway. These findings were confirmed in transient transfection assays using a plasmid containing the PAP-I promoter linked to the chloramphenicol acetyltransferase reporter gene. Then the relationship between PAP-I induction and protection against cell damage during oxidative stress was considered. Constitutive PAP-I expression in AR4-2J cells after transfection with PAP-I complementary DNA conferred significant resistance to apoptosis induced by low doses of H2O2 but not to necrosis induced by high doses of H2O2.

CONCLUSIONS

These results suggest that during oxidative stress, PAP-I might be part of a mechanism of pancreatic cell protection against apoptosis.

Cloning and expression of the rat p8 cDNA, a new gene activated in pancreas during the acute phase of pancreatitis, pancreatic development, and regeneration, and which promotes cellular growth

To characterize at the molecular level the pancreatic emergency program set up by the pancreatic cells in response to pancreatitis, we have developed a strategy in which the phenotype of the pancreatitis affected pancreas is established by characterization of a large number of its transcripts. Herein, we describe the cloning, sequence, and expression of a new gene, named p8, which is strongly activated in pancreatic acinar cells during the acute phase of pancreatitis, in developing pancreas and during pancreatic regeneration. In acinar cells, p8 mRNA is expressed rapidly and specifically in response to cellular pancreatitis-induced injury; its induction occurred almost similarly in edematous and necrohemorrhagic pancreatitis, indicating that p8 mRNA is maximally activated even in response to a mild pancreatic injury. Furthermore, in vitro studies suggest that p8 mRNA is induced in pancreatic and non-pancreatic cells in response to some apoptotic stimuli. p8 acts as a promoter of cellular growth factor when its cDNA is transfected into COS-7 and AR4-2J cells. Although we failed to identify p8-related sequences, analysis of its primary and secondary structure suggests that p8 is a basic helix-turn-helix-containing gene with slight homology to several homeotic genes and sufficient signal to be targeted to the nucleus. We therefore propose p8 as a putative transcriptional factor which can regulate pancreatic growth.

The pancreatitis-associated protein I promoter allows targeting to the pancreas of a foreign gene, whose expression is up-regulated during pancreatic inflammation

The pancreatitis-associated protein I (PAP I) is a pancreatic secretory protein expressed in pancreas during acute pancreatitis but not in the healthy pancreas. The promoter of the PAP I gene thus represents a potential candidate to drive expression of therapeutic molecules to the diseased pancreas. In this work, we have constructed recombinant adenoviruses harboring the chloramphenicol acetyltransferase (CAT) gene driven by several fragments of the PAP I promoter and have characterized their properties in vitro and in vivo. In vitro studies showed that the transduction of the pancreatic cell line AR-42J with these adenoviruses led to low levels of CAT activity in basal conditions. After stimulation with a combination of interleukin-6 and dexamethasone or after induction of oxidative stress, CAT activity was strongly induced, a characteristic of the endogenous PAP I gene. Stimulation was maximal when constructs comprised 1253 base pairs of the PAP I promoter, upstream from initiation of transcription, and decreased with shorter fragments of 317, 180, 118 or 61 base pairs. The recombinant adenovirus containing the CAT gene under the control of the PAP I promoter fragment (-1253/+10) was also tested in vivo. Following administration by intravenous injection into mice, CAT activity was measured in several tissues 96 h later. In healthy animals, low but significant CAT activity was detected in pancreas, compared with near background values observed in the other tissues. When experimental acute pancreatitis was induced, CAT expression was strongly enhanced only in pancreas. In control experiments with adenoviruses in which the CAT gene was driven by the cytomegalovirus promoter, higher levels of expression were observed in all tissues. Expression was not modified after induction of acute pancreatitis. In conclusion, this study shows that (i) a recombinant adenovirus containing a fragment of the PAP I promoter allows specific targeting of a reporter gene to the mouse pancreas and (ii) expression of the reporter gene in pancreas is induced during acute pancreatitis. Adenovirus-mediated gene therapy of acute pancreatitis is therefore conceivable.

Two transcripts are generated from the pancreatitis associated protein II gene by alternative splicing in the 5' untranslated region

We have previously reported the coding sequence of the rat PAP II mRNA. We show in this paper the existence in rat pancreas of two forms of PAP II mRNA with identical coding sequence but a different 5'-untranslated region. We demonstrate that this is the result of a differential splicing.

Analysis of 2166 clones from a human colorectal cancer cDNA library by partial sequencing

Large scale sequencing of cDNAs from a tissue-specific library provides information on the functional phenotype of that tissue and the clones constitute a reservoir of biological markers. For these reasons, we have randomly sequenced 2166 clones of a cDNA library constructed with human colorectal cancer mRNAs. Database searches indicated that 1014 of the cDNAs represented known human genes or human homologs of other genes, 142 sequences corresponded to known ESTs, 119 sequences corresponded to 28S rRNA, repetitive sequences or poly(A) stretches only, and 891 corresponded to unknown transcripts representing the products of 740 new genes. Preliminary studies demonstrated that expression of some of them was altered in cancer. That cDNA collection is therefore a source of potential markers of colorectal cancer.